Remember the last time you got on a train, only to find all the seats occupied by people … and their bags? Boy, bags really do like aisle seats, you may have said to yourself. Or maybe you just shook your head and moved on to the next car, annoyed by the passive-aggressiveness of it all: “Seat’s taken!” the bags scream in silence, while their owners turn and stare out the windows.

You might deplore such behavior when you’re the one schlepping down the aisle in search of an open seat, but admit it, you’re probably guilty of piling your suitcase next to you too, when you’re the first on board. So why do we do it?

That’s the question Yale University doctoral student Esther C. Kim explored in a new study published in the journal Symbolic Interaction. The bag-in-seat move is just one among a collection of similar strategies she observed, which she calls “nonsocial transient behavior.” In less academic terms, they’re tactics people use while traveling in an attempt to keep strangers at arm’s length, or farther away.

Kim cataloged these various habits over two years of research. Like any good ethnographer, she lived the life of her study subjects, taking multiple cross-country bus rides — from Connecticut to New Mexico, a trip that took two days and 17 hours; California to Illinois; Colorado to New York; Texas to Nevada. She spent hours stuck in dingy terminals, used rusty washrooms and took notes on the sly, watching people through the slit between bus seats to collect her data. (Not since Menelaus pursued his Helen has one showed such commitment to a cause.)

In the resulting paper, Kim lays out the hows and whys of nonsocial transient behavior, but first, she differentiates it from previous and seemingly comparable concepts like civil inattention, i.e., when strangers in close proximity try to respectfully keep their distance. Civil inattention drives phenomena like “elevator osmosis,” for example: if there are four people in a car, they will politely arrange themselves in a square, without coordination or eye contact. As people get off, the square becomes a triangle, then the triangle become a hypotenuse, each remaining passenger reshuffling to provide maximum space and privacy for the others.

With nonsocial transient behavior, however, “respect is not a concern,” Kim writes. It’s not about affording other people the courtesy of elbow room; instead, it’s telling your neighbors “overtly not to step into [your] territory.” It is a performance, Kim says, and not a civil one.

The basic rules of bus travel help set this more antagonistic scene: as Kim discovered, every row must be occupied before you sit next to someone. Anyone who defies this rule is considered a “weirdo.” If it is announced that the bus will be full and that all seats must be made available, then the goal shifts and becomes sitting next to a “normal” person. Normal, according to one bus traveler, “means someone who ‘doesn’t look crazy,’ will not talk much, and probably will not smell bad.” The assumption, Kim explains, “is that sitting next to a ‘normal’ person who is not ‘crazy’ helps to avoid discomfort.”

Avoiding discomfort, whether physical or mental, is why people go to such lengths to protect their space. Kim spoke with an “experienced rider” named Loretta about how she kept potential encroachers from invading the seat next-door. Her tactics included avoiding eye contact; stretching her legs onto the neighboring seat; sitting in the aisle seat, blasting her iPod and pretending not to hear people asking for the window seat; placing many small items on the other seat so it was clearly “not worth their time” for passengers to wait for Loretta to clear it; pretending to sleep; and looking out the window with an off-putting “blank stare.” A more direct method, though questionable given certainchapters in Greyhound’s history, is using the don’t-mess-with-me look, or the “hate stare.” Kim tried many of these methods herself and said she found them “quite effective.”

These peevish schemes are particular to travelers, Kim found. You wouldn’t find the same behavior, say, at a cafe. There are three main reasons, Kim says, that travelers tend to be so antisocial: uncertainty about strangers (other travelers might be “crazies” or be out to steal your stuff); aggravation over the lack of privacy or absence of personal space; and exhaustion. Travelers may be tired, stressed out and jaded by the vagaries of long-distance trips, and usually, they expect other passengers to be too.

Nonsocial transient behavior is really all about increasing one’s own comfort, however; it has little to do with considerations for others — for instance, assuming other travelers are tired and would prefer not to be bothered. For the most part, Kim writes, “As strangers on the bus, individuals have no incentive to invest their time or energy in others.”

Kim’s findings are specific to her experiences riding cross-country buses — those long, confined journeys that make people particularly moody and frustrated — but anyone who has even gone three stops on the subway or city bus will have experienced the same sad kind of self-preservation. People also do it in shuttles from city centers to the airport or on airlines like Southwest where seats are first-come-first-served.

There isn’t much we can do about a fairly natural reaction. “Confinement in a small spaces without privacy,” Kim explains, simply causes “people to actively disengage.” But at the very least, perhaps you can actively disengage your bags from the aisle seat.

I wonder if there are cultural differences -- this study only took place in the US. I noticed when riding Parisian commuter trains during rush hour while on a visit that people were a lot more likely to look up, smile, and willingly move their stuff than in New York City.

There is absolutely nothing enlightening in the findings of this research, all common knowledge. Maybe a comparative study of passenger behavior in the past or of those in different cultures will make the research more meaningful.

I am surprised no one mentioned being a woman on public transportation. The methods mentioned in the article are to keep men from sitting next to you, because they want to talk, they touch your arm, get in to close -- and if you don't respond in a positive fashion they get hostile, start to yell - call you a bitch..... after this happens a few times, you don't want people sitting next to you, or go out of your way to sit next to a woman... and you know if a woman ask another woman to move her purse - she will, she understands.

This is what I was waiting for her to mention while reading the article, and was quite surprised it wasn't addressed. Traveling as alone as a female has a variety of risks that after a certain amount of experience you take actions to reduce in the future, such as avoiding contact in transit. I traveled a lot from ages 18-24ish and was constantly ending up sitting next to older men on planes who felt this need to be domineering or "protective" which basically meant stalking me for the rest of the trip. It happens less now as I'm near 30 (presumably I look less naive and more wary), but the damage is done. After hiding in women's restrooms to escape a creepy male follower so many times, it has become habit to avoid sitting next to males whenever possible, even though I'm sure most are fine. It's unfortunate, but it happens. Often.

As Talendria (comment below) mentions, this rude behavior is seen in many different contexts. At least the one described here, on the bus, seems mostly sensible to me. The anti-social behavior which bothers me to the point of outrage is when at a pool or a beach, people put their towel on a public lounge chair and then leave to swim for several hours.

Just wow, Germans are notorious for this. I have been to German pools/thermal baths and there are hundreds of EMPTY chairs, but no where to sit! Arghhh. I just want to go around and take all the towels and throw them in the pool. I guess this is on my bucket list!

I think anyone who intentionally takes a bus cross country for two years for no other reason than to study why people don't want to sit next to other people on the bus is a weirdo, and I would not want to sit next to her on the bus.

Some people obsess over the strangest things. I think I will conduct a study of why someone would study why people won't sit next to strangers on a bus. That will be my new obsession.

Maybe I'll do a study on why people would read an article, that they can clearly deduce what it's about from the title, then complain about how dumb it was. I'll be there's an awful lot of people out there like that. We can compare notes!

Nice study...but this is all subjective to one person's observation of behavioral manifestation of a bunch of strangers. While this kin of qualitative study is nice and good, an interesting extension of the study would have been to work with some lab base findings. I am also amazed that there is no mention of culture and ethnicity in the study. Do people from all cultural and ethnic background exhibit this kind behavior? are those who have stayed in the country for longer period are more likely to be antisocial travelers? Answer those questions and then this will be a study worth reading. Also what is the sample size in the study?

Guess I am the naive, but the stranger next to you, could show up to be a friend for life, a messenger of important information, an introduction to new worlds. But anxiety has taken over, and we built societies and social orders based on enstrangement and fear.

I've been taking the Greyhound a lot lately, and I've been surprised by how friendly and fascinating my seatmates have been. People on buses are much more sociable than people on planes.

One time the bus was nearly full, and I walked by a seat next to a very tall, muscular guy dressed in black (i.e., he looked a little intimidating). He said to me, 'You can sit here if you want,' which I'd never heard anyone say before. So I sat down next to him, and we ended up talking for three hours, until he got off the bus. He was very kind and respectful.

Another time I sat next to a 90-year-old woman who had incredibly interesting stories about her childhood growing up on a ranch in Idaho. I've also sat next to a sweet 15-year-old refugee from Libya; a 20-year-old who was in the army; and a Korean woman studying English. I have come to prefer taking a bus over taking a plane--it's a much more human experience.

Maybe there was garbage left in other available rows. Maybe, like on my train, there's seats facing different directions and that person gets motion sick unless its facing forward and they'd rather sit next to someone in a forward seat than risk vomiting in a row all to themselves. Maybe they felt like they were being followed by someone threatening and one way to make sure the stalker can't sit next to them is by sitting next to someone else. There's a million rational reasons someone might pick the seat they do and its none of my business why. I get one seat, that's it. Concerning myself with other people in other seats is actually whats really nosy. I just keep reading my kindle.

Being a non-white student this kind of racism happened to me a lot of times in a white college town movie theater. They all lied to me that their "friends" would come back to these seats but I observed the seats remain unoccupied the whole time.

Overstating the obvious; passing off everyday occurrences as research observations - has scientific thesis writing become a manufacturing process, made to sound respectable with pseudo intellectual jargon?

I wouldn't say this behavior is peculiar to travelers. You'll witness the same phenomenon at movies, parades, pools, beaches, etc. People try to create a physical buffer between themselves and others--and with good reason. Strangers often have little regard for others. They'll blow cigarette smoke in your face, step on your kids, drop luggage on your head, talk over you to a person sitting on your other side. In our society, there's no penalty for rudeness, so the only way to protect yourself and your family is to keep people at a distance.